基于移相脉冲宽度调制控制的串联谐振式塑料薄膜表面处理电源的研制

塑料薄膜表面处理负载是一种非线性变化的容性负载,随着放电的增强,负载等效电容增大。针对负载这一特点,研制一台基于移相脉冲宽度调制(PS-PWM)控制的塑料薄膜表面处理电源,实现对负载谐振频率的闭环跟踪。采用PS-PWM控制的塑料薄膜表面处理电源简单,紧凑,可获得很高的效率,采用二极管直接整流方式,克服了因晶闸管整流所带来的尺寸和成本问题。这种高频电源较好地实现了开关管的零电压(ZVS)软化,得到了较宽的调功范围。文中给出了该电源对塑料薄膜表面处理的实际结果,并验证了其有效性。

Design of Phase-shifted Pulse Width Modulated (PS-PWM) Controlled Series Resonant Inverter for Plastic Film Surface Treatment

The plastic film surface treatment load is represented as a varied nonlinear capacitive load, and its equivalent capacitance becomes higher as the discharge is strengthened. Aimed at the characteristics of the load, a phase- shifted pulse width modulated (PS-PWM) series resonant inverter is developed for the plastic film surface treatment, and the tracing of load resonant frequency is realized with a close-loop control. The PS-PWM inverter makes the system of plastic film surface treatment simple and compact thus leading to higher efficiency. A diode rectifier is used, thus it can reduce the size and cost of the equipment with thyristor rectifier. The high frequency inverter used here can achieve zero voltage soft switching (ZVS) and wide power regulation range. The results of the plastic film surface treatment by this inverter are shown to verify the validity of the method.